User Guide

10
SnoTrace
™
RGS
™
Systems for Roof and Gutter Snow and Ice Melting
General Specification
Part 1 General
Furnish and install a complete UL Listed system
of heaters and components approved specifically
for snow and ice melting of roofs, gutters and
downspouts. The heat tracing system shall conform
to ANSI/IEEE Standard 515 and IEEE Standard 515.1.
Part 2 Products
1. The heating cable shall be of parallel resistance
construction capable of being cut to length and
terminated in the field. Series resistance cables
will not be allowed.
2. The self-regulating heater shall consist of two
1.3 mm
2
(16 AWG) nickel-plated copper bus
wires embedded in parallel in a radiation cross-
linked self-regulating conductive polymer core
specifically designed for snow and ice melting.
The heater shall be capable of varying its heat
output along its entire length. Power output of
the heater shall be 39 W/m @ 0°C (12 W/ft @ 32°F)
when surrounded by snow or ice and 20 W/m @
0°C (6 W/ft @ 32°F) when exposed to dry air. The
heater shall be covered by a polyolefin dielectric
jacket, a tinned copper braid, and a UV stabilized
polyolefin outer jacket.
3. The heater shall operate on a line voltage of
(select: 110-120 or 208-277) Vac without the use of
transformers.
4. Power connections shall be made in UL Listed
junction boxes (by others) as described under Part
6, Installation.
5. All heating cable core will be permanently marked
with the manufacturer’s identification number for
traceability.
6. Acceptable products and manufacturers are
SnoTrace
™
RGS
™
as manufactured by Thermon.
7. Refer to the manufacturer’s “Roof and Gutter
Snow and Ice Melting Design Guide” for design
details, maximum circuit lengths and accessory
information.
Part 3 Power Distribution and Control
1. Circuit breakers supplying power to the heat
tracing must be equipped with 30 mA minimum
ground fault equipment protection.
2. Systems with four or more circuits shall utilize
a dedicated power distribution and contactor
panel provided by the roof and gutter snow and
ice melting system manufacturer. Included in
each panel will be a main breaker, contactor and
30 mA ground fault branch circuit breakers. The
panel enclosure will be rated for NEMA (select:
12 for indoors or 4 for outdoors) service. All panel
components shall be UL Listed and/or CSA
certified.
3. Power to the roof and gutter snow and ice
melting circuits will be controlled by (select: a
manual switch, an ambient sensing thermostat
or an automatic snow/ice sensor) designed to
control the heating cable load or the coil of a
contactor.
Part 4 System Performance
1. Amount of cable required to maintain a clear path
for melted snow and ice to drain shall be based
on size and shape of protected area and expected
weather conditions.
2. Design and layout must comply with Section
6.2, Roof and Gutter De-Icing, of the IEEE
Standard 515.1, Recommended Practice for the
Testing, Design, Installation, and Maintenance
fo Electrical Resistance Heat Tracing for
Commercial Applications.
3. Power retention of the heating element shall be
in accordance with IEEE Standard 515.1, Item 4.2.6,
Performance After Thermal Aging.
Part 5 Manufacturer
1. The manufacturer shall demonstrate experience
designing snow and ice melting systems. This
experience may be documented with a list of
_____ engineered projects with a minimum of
150 m (500 ft) of heating cable.
2. Manufacturer’s Quality Assurance Program shall
be certified to the ISO 9001 Standard.
Part 6 Installation
1. Heating cable shall be installed directly on
the roof or in gutters or downspouts per
manufacturer’s installation guide. Attachment
shall be made with roof clips, downspout cable
hangers and/or aluminum tape as required to
secure cable. All attachments should be made
to maintain the integrity of the roof by use of
sealants or adhesives compatible with the roofing
materials.
2. Power connections shall be located in NEMA 4 or
4X junction boxes (by others).
3. All installations and terminations must comply
with all applicable regulations outlined in the NEC
and CEC, and any other applicable national and
local electrical codes.
4. Circuit breakers supplying power to the heat
tracing must be equipped with 30 mA minimum
ground fault equipment protection.
Part 7 Testing
1. Heating cable shall be tested with a 2,500
Vdc megohmeter (megger) between the
heating cable bus wires and the heating cable
metallic braid. While a 2,500 Vdc megger test is
recommended, the minimum acceptable level for
testing is 1,000 Vdc. This test should be performed
a minimum of two times:
a. Prior to installation while the cable is still on
reel(s).
b. After installation of heating cable and
completion of circuit fabrication kits but prior to
connection to power.
2. The minimum acceptable level for the megger
readings is 20 megohms regardless of the circuit
length.
3. Results of the megger readings should be
recorded and submitted to the construction
manager.